The present invention relates to a posture detecting device provided on a data acquiring device such as a surveying instrument, an image acquiring device and the like, requiring a posture detection and a data acquiring device provided with the posture detecting device.
As the data acquiring device for detecting a posture of the surveying instrument, for instance, for detecting a tilting with respect to the horizontal, a tilt sensor is known, for instance. Although the tilt sensor can detect the horizontal with high accuracy, responsiveness is poor and several seconds are required until the tilt sensor becomes stable. Further, in the tilt sensor, a measurement range is small, and a large tilting cannot be measured.
Further, as a sensor capable of detecting a tilting with high responsiveness, an acceleration sensor is known. Although a detection range is wider than the tilt sensor, detection accuracy is poor, and in order to set as an absolute reference such as the horizontal or the like, the detection accuracy does not satisfy a surveying level.
Further, in the conventional type, a posture detecting device has a limited range of detection of a tilt angle, and in all postures such as a case where the device is vertical or inverse or the like, the tilt angle cannot be detected.